Displacement pump pressure feedback control and method of control

ABSTRACT

A method of controlling an actuation pump including monitoring a supply pressure of a pump, monitoring an outlet pressure of the pump, commanding a motor by a motor controller, which receives the monitored pressures, to drive the pump at a speed based on a comparison of the supply pressure and the outlet pressure of the pump.

BACKGROUND Technological Field

The present disclosure relates to a method of controlling a positivedisplacement pump, and specifically to controlling a pump using apressure differential.

Description of Related Art

Positive displacement pumps produce large parasitic losses in airbreathing engine fluid systems. Traditionally pumps are controlled basedon their mechanical linkage to engine speed and are sized for to meetextreme conditions which are rarely reached or operated at. This leadsto oversizing, which then requires other oversized components andunneeded flow capacity in the vast majority of operational conditions.This unneeded flow is a source of parasitic losses within an engineenvironment. While conventional design, operation, and sizing methodshave generally been considered satisfactory for their intended purpose,there is still a need in the art for improved pump controls and sizingmethods. The present disclosure provides a solution for this need.

SUMMARY OF THE INVENTION

A method of controlling a pump is disclosed. The method includesmonitoring a supply pressure of a pump, monitoring an outlet pressure ofthe pump, and commanding a motor to drive the pump at a speed based on acomparison of the supply pressure and the outlet pressure of the pump,where the pump is a positive displacement pump and the motor is anelectric motor. The method can include receiving an initial pressurecommand from an engine controller. Commanding the motor can includechanging a speed of the motor in response to a change from the initialpressure command from the engine controller and/or a change indifferential pressure between the supply pressure and the outletpressure.

It is also considered that the monitored pressures can be sent aselectrical signals directly to a motor controller to electrical anddirectly sent back to the motor controller command the motor to drivethe pump. The method can also include actuating a stator vane of anaircraft based on an increased or decreased pressure from the pump.

A system for operating the method described above is also disclosed. Thesystem includes a motor, a pump operatively coupled to the motor to bedriven by the motor, wherein the pump includes an input side and anoutput side, a pressure sensor to monitor a pressure difference betweenthe input side and output side of the pump, and a motor controller tocommand the motor based on the detected pressure difference across thepump and monitor the pressure sensor. The motor controller can beoperatively coupled to an engine controller, where the engine controllercan be configured to provide a pressure command to the motor controllerbased on power required to accomplish an actuation task.

The pressure sensor can be configured to measure supply pressure andoutlet pressure of the pump. The pressure sensor can include a firstpressure sensing element located on a supply side of the pump, and asecond pressure sensing element located on an output side of the pump.The pressure sensor can be a differential pressure sensor. It is alsoconsidered that the pressure sensor can include two independent sensorswherein each of the two independent sensors is configured to measureabsolute pressure. The system can be part of an actuation system of anaircraft for actuating a stator vane or other air guiding element.

The motor controller used in the method includes non-transitory computerreadable medium comprising computer executable instructions to executethe steps of the method described above. The motor controller can beconfigured to receive a pressure command from the engine controller toproduce power required to accomplish an actuation task, wherein theengine controller can also be responsible for controlling an aircraftengine.

These and other features of the systems and methods of the subjectdisclosure will become more readily apparent to those skilled in the artfrom the following detailed description of the preferred embodimentstaken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those skilled in the art to which the subject disclosureappertains will readily understand how to make and use the devices andmethods of the subject disclosure without undue experimentation,embodiments thereof will be described in detail herein below withreference to certain figures, wherein:

FIG. 1 is a schematic depiction of a pump motor controller in accordancewith the disclosure.

DETAILED DESCRIPTION

Reference will now be made to the drawings wherein like referencenumerals identify similar structural features or aspects of the subjectdisclosure. For purposes of explanation and illustration, and notlimitation, a schematic view of an exemplary embodiment of a system forcontrolling a pump based on a pressure difference between an input andoutput pressure on the pump in accordance with the disclosure is shownin FIG. 1 and is designated generally by reference character 100. Thesystem and methods described herein allow for engine actuation systemsto only consume power needed to accomplish an actuation task based oninstant operational constraints, instead of depending on unrelatedengine speed relationships, making for more efficient systems.

Referring now to FIG. 1 , a schematic of system 100 is shown. The system100 is part of an aircraft actuation system coupled to an aircraftengine, and is considered to be useful in both an actuation system and amain fuel pump application. Any system where a pressure needs to bemanipulated to influence system functionality can benefit from thisarchitecture. The system 100 includes a motor 102, a pump 104operatively coupled to and controlled by the motor 102. The motor 102 isan electric motor, and the pump 104 is a positive displacement pump.

A pressure sensor having a pair of sensing elements 106 a, 106 b is usedto monitor the pressure difference across pump 104. One pressure sensingelement 106 a is located on an input side 105 of pump 104 to sense inputpressure of the pump 104. A second pressure sensing element 106 b islocated on an output side 107 of the pump 104 in order to sense outputpressure from the pump 104. This type of pressure sensor can be adifferential pressure sensor spanning a pump membrane in order to outputa difference in pressures by referencing pressure with another locationwhere pressure is also measure. It is also considered that each of thesensing elements 106 a, 106 b can be independent pressure sensors tomeasure and produce absolute pressure readings. The sensors 106 a/b canbe separate pressure transducers, each connected to the microcontroller108 to monitor a pressure difference across the pump 104. Each one ofthe pressures sensing elements at each of the locations shown in FIG. 1are both connected to a single differential pressure transducer 109. Thedifferential pressure transducer 109 is itself connected to themicrocontroller 108 to convey input indicative of the pressuredifferential between the inlet and outlet of the pump 104. A motorcontroller 108 is operatively coupled to the motor 102 in order tocommand the motor 102 to increase or decrease speeds based on targetedpressure commands received from a master engine controller 110, andbased on the input from the pressure sensors 106 a, 106 b. The motorcontroller 108 is programmed to compare the target pressure readingsversus the outputs, and increase or decrease the speed of the motor 102accordingly.

The motor controller 108 includes a non-transitory computer readablemedium which includes computer executable instructions to monitor asupply pressure of the pump 104, monitor an outlet pressure of the pump104, and monitor and control the speed of the electric motor 102 basedon a comparison of the supply pressure and the outlet pressure of thepump.

The methods and systems of the present disclosure, as described aboveand shown in the drawings, provide for a method of designing and sizingan displacement pump system that is more attuned to the specific task itis required to perform. While the apparatus and methods of the subjectdisclosure have been shown and described with reference to preferredembodiments, those skilled in the art will readily appreciate thatchanges and/or modifications may be made thereto without departing fromthe scope of the subject disclosure.

What is claimed is:
 1. A method of controlling a pump comprising:monitoring a supply pressure of a pump; monitoring an outlet pressure ofthe pump; and commanding a motor to drive the pump at a speed based on acomparison of the supply pressure and the outlet pressure of the pump.2. The method of claim 1, further comprising receiving an initialpressure command from an engine controller.
 3. The method of claim 1,wherein the motor is an electric motor.
 4. The method of claim 1,wherein the pump is a positive displacement pump.
 5. The method of claim1, wherein commanding the motor includes changing a speed of the motorin response to a change from the initial pressure command from theengine controller and/or a change in differential pressure between thesupply pressure and the outlet pressure.
 6. The method of claim 1,wherein the monitored pressures are sent as electrical signals directlyto a motor controller to electrical and directly sent back to the motorcontroller command the motor to drive the pump.
 7. The method of claim1, further comprising actuating a stator vane of an aircraft based on anincreased or decreased pressure from the pump.
 8. A system comprising: amotor; a pump operatively coupled to the motor to be driven by themotor, wherein the pump includes an input side and an output side; apressure sensor to monitor a pressure difference between the input sideand output side of the pump; and a motor controller to command the motorbased on the detected pressure difference across the pump and monitorthe pressure sensor.
 9. The system of claim 8, wherein the motorcontroller is operatively coupled to an engine controller.
 10. Thesystem of claim 9, wherein the engine controller is configured toprovide a pressure command to the motor controller based on powerrequired to accomplish an actuation task.
 11. The system of claim 8,wherein the pressure sensor is configured to measure supply pressure andoutlet pressure of the pump.
 12. The system of claim 8, wherein thepressure sensor includes a first pressure sensing element located on asupply side of the pump, and a second pressure sensing element locatedon an output side of the pump.
 13. The system of claim 8, wherein thepressure sensor is a differential pressure sensor.
 14. The system ofclaim 8, wherein the pressure sensor includes two independent sensorswherein each of the two independent sensors is configured to measureabsolute pressure.
 15. The system of claim 8, wherein the system is partof an actuation system of an aircraft for actuating a stator vane orother air guiding element.
 16. A motor controller for controlling a pumppressure comprising: a non-transitory computer readable mediumcomprising computer executable instructions to: monitor a supplypressure of the pump; monitor an outlet pressure of the pump; andcommand a motor based on a comparison of the supply pressure and theoutlet pressure of the pump.
 17. The microcontroller of claim 16,wherein the pump is a positive displacement pump.
 18. Themicrocontroller of claim 16, wherein the motor controller is configuredto receive a pressure command from the engine controller to producepower required to accomplish an actuation task.
 19. The microcontrollerof claim 16, wherein the engine controller controls an aircraft engine.